Fluorosilicone hydrogels

ABSTRACT

Novel fluorosiloxane-containing monomers are disclosed which are especially useful for the preparation of biomedical materials such as contact lenses.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to novel polymeric compositions and moreparticularly to contact lenses made therefrom. The invention furtherparticularly relates to polysiloxane-containing monomers having at leastone polar fluorinated side chain. The monomers described herein can beused to make "hard" or "soft" contact lenses, intraocular implants, aswell as other prostheses, and more particularly "soft" hydrogel contactlenses.

2. Background

In the field of contact lenses, various factors must combine to yield amaterial that has appropriate characteristics. Oxygen permeability,wettability, material strength and stability are but a few of thefactors which must be carefully balanced to achieve a useable contactlens. Since the cornea receives its oxygen supply exclusively fromcontact with the atmosphere, good oxygen permeability is a criticalcharacteristic for any contact lens material. Wettability also isimportant in that, if the lens is not sufficiently wettable, it does notremain lubricated and therefore cannot be worn comfortably in the eye.The optimum contact lens would therefore, have both excellent oxygenpermeability, and excellent tear fluid wettability.

Polysiloxane materials are useful materials for making contact lensesdue to, among other properties, their excellent oxygen permeability. SeeU.S. Pat. Nos. 4,153,641 and 4,189,546. However polysiloxanes aregenerally hydrophobic. Certain hydrophilic functional groups may beattached to polysiloxane-containing monomers, or prepolymers to improvetheir wettability. See U.S. Pat. Nos. 4,260,725 and 4,259,467. However,many hydrophilic comonomers are known to be incompatible with thepolysiloxane monomers in the monomer mix, and require the presence ofsolubilizers and compatibilizers for the monomer mix properlypolymerize. Without such compatibilizers, the copolymer may notpolymerize at all, risking varying degrees of phase separation whichrenders the polymerized material opaque.

In addition to oxygen permeability, wettability and compatibilityrequirements, contact lens materials must resist deposits. Somepolysiloxane materials tend to accumulate deposits. Fluorinating certainpolysiloxanes monomers is known to improve deposit resistance. See, forexample U.S. Pat. Nos. 4,440,918, 4,990,582, 4,954,587, 5,079,319 and5,010,141.

Fluorinated polysiloxanes with useful properties for non-hydrogelcontact lenses are disclosed in U.S. Pat. Nos. 4,810,764 and 5,142,009.In further experimentation with these materials, it was determined thata hydrogel having the oxygen permeability advantages imparted by thesiloxane group, and the lipid resistance imparted by the fluorinatedgroups would be particularly advantageous. However, because thefluorinated polysiloxane monomers are difficult to solubilize in thehydrophilic monomers used, it is difficult to make viable hydrogelformulations for contact lenses using this approach. If comonomers arenot sufficiently soluble in one another, phase separation will occurrendering the polymerized material opaque. Such a result is notdesirable for a material which must be transparent, such as a contactlens.

Compatibilizers or solubilizers such as methyl ethyl ketone (MEK) havebeen used to get certain fluorinated siloxane-containing monomers intosolution to form films or lenses. However, such solubilizers andcompatibilizers often affect purity and must be extracted from theresulting polymer. Such extraction requires additional processing steps.Further, if there is a large difference in polarity between thesiloxane-containing monomer and the hydrophilic monomer, even thepresence of solubilizers such as MEK will not keep the comonomers insolution.

Therefore, a hydrolytically stable polymeric system comprising thebenefits of polysiloxane-containing monomers for oxygen permeability andmaterial strength, and fluorinated side-groups for resistance withoutuse of compatibilizers or solubilizers would be of great advantage for ahydrogel formulation.

SUMMARY OF THE INVENTION

It has now been discovered that the compatibility and solubility offluorinated polysiloxanes in hydrophilic comonomers can be greatlyimproved by attaching to a siloxane group in a polysiloxane-containingmonomer, a polar fluorinated graft or side group having a hydrogen atomattached to a terminal difluoro-substituted carbon atom. When thishydrogen atom is present on the terminal difluorinated carbon atom, thefluorinated polysiloxane is rendered soluble in hydrophilic comonomersto such an extent that no additional compatibilizing or solubilizingagents are needed. When the terminal hydrogen atom is replaced with afluoro group, the solubility is drastically affected such that thehydrophilic comonomers are insoluble in the fully fluorinatedsiloxane-containing monomer.

DETAILED DESCRIPTION OF THE INVENTION

The fluorinated polysiloxane-containing monomers disclosed hereinsurprisingly display outstanding compatibility by being highly solublein various hydrophilic compounds, such as N-vinyl pyrrolidone (NVP) andN,N-dimethyl acrylamide (DMA), without the need for additionalcompatibilizers or solubilizers.

As used herein, the term "side group" refers to any chain branching froma siloxane group, and may be a side chain when the siloxane is in thebackbone of the polymeric structure. When the siloxane group is not inthe backbone, the fluorinated strand or chain which branches out fromthe siloxane group becomes a side chain off of the siloxane side chain.

The "terminal" carbon atom refers to the carbon atom located at aposition furthest from the siloxane group to which the fluorinatedstrand, or side group is attached.

It was discovered and is disclosed herein that when the polarfluorinated group, --(CF₂)_(z) H, is placed at the end of a side groupattached to a siloxane-containing monomer, the entire siloxane monomerto which the side group is attached is rendered highly soluble inhydrophilic monomers, such as NVP. When the hydrogen atom in theterminal fluorinated carbon atom is replaced with a fluoro group, thesiloxane-containing monomer is significantly less soluble, or notsoluble at all in the hydrophilic monomer present.

In one embodiment of the present invention, fluorinatedsiloxane-containing monomers are disclosed having at least onefluorinated side group, said side group having the general schematicrepresentation (I):

    --D--(CF.sub.2).sub.z H                                    I.

wherein

z is 1 to 20; and

D is an alkyl or alkylene group having 1 to 10 carbon atoms and whichmay have ether linkages between carbon atoms.

In a further embodiment, the fluorinated siloxane-containing monomershave at least one fluorinated side group and have a moiety of thefollowing general schematic representation (II): ##STR1## wherein: D isan alkyl or alkylene group having 1 to 10 carbon atoms and which mayhave ether linkages between carbon atoms;

x is ≧0;

y is ≧1;

x+y=2 to 1000; and

z is 1 to 20.

More preferred are the fluorinated siloxane-containing monomers havingthe following general schematic representation (III): ##STR2## wherein:R is an alkyl or alkylene group having 1 to 10 carbon atoms and whichmay have ether linkages between carbon atoms;

R₁ -R₄ may independently be a monovalent hydrocarbon radical or ahalogen substituted monovalent hydrocarbon radical having 1 to 18 carbonatoms which may have ether linkages between carbon atoms;

x is ≧0;

y is ≧1;

x+y=2 to 1000; and

z is 1 to 20; and

R₅ is a fluorinated side chain having the general schematicrepresentation:

    --D--(CF.sub.2).sub.z --H

wherein z is 1 to 20;

D is an alkyl or alkylene group having 1 to 10 carbon atoms and whichmay have ether linkages between carbon atoms; and

A is an activated unsaturated group, such as an ester or amide of anacrylic or a methacrylic acid or is a group represented by the generalformula: ##STR3## wherein Y is --O--, --S-- or --NH--;

Preferably, the fluorinated side group is represented by the formula:

    --CH.sub.2 --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --(CF.sub.2).sub.z --H

where

z is 1 to 20.

One preferred fluorinated siloxane-containing monomer, is preparedaccording to the following reaction scheme: ##STR4## where y is 10, 25and 40;

x+y is 100; and

z is 4 or 6

In still a further embodiment of the present invention, the fluorinatedsiloxane-containing monomers are fluorinated bulky polysiloxanylalkyl(meth)acrylate monomers represented by the general schematicrepresentation: ##STR5## wherein A is an activated unsaturated group,such as an ester or amide of an acrylic or a methacrylic acid;

R₆ is CH₃ or H;

R is an alkyl or alkylene group having 1 to 10 carbon atoms and whichmay have ether linkages between carbon atoms;

D is a alkyl or alkylene group having 1 to 10 carbon atoms and which mayhave ether linkages between carbon atoms;

x is 1, 2 or 3;

y is 0, 1, or 2; and

x+y=3.

Also preferred are the fluorinated bulky polysiloxanylalkyl monomers ofthe following formula: ##STR6## wherein R₇ is CH₂ ; and

x is 1, 2 or 3;

y is 0, 1 or 2; and

x+y=3.

The fluorinated polysiloxane-containing monomers of the presentinvention combine the desirable features of known hydrophilic side chainpolysiloxanes, such as relative compatibility with hydrophilic monomers,with improved deposit resistance from the fluorinated group. Desiredproperties of the lenses may be affected and controlled. For example, byaltering the relative ratio of the comonomers (the aforementionedfluorinated polysiloxane monomer to the hydrophilic monomer ormonomers), certain hydrogel characteristics in the polymerizedfluorinated polysiloxane copolymer may be altered.

The relative softness or hardness of the contact lenses fabricated fromthe resulting polymers of this invention can be varied by decreasing orincreasing the molecular weight of the polysiloxane monomer end-cappedwith the activated unsaturated group or by varying the percent of thecomonomers present. Generally, as the ratio of polysiloxane units toend-cap units increases, the softness of the material increases.

The present invention contemplates the use of the fluorinatedpolysiloxane monomer for both "hard" and "soft" contact lenses, thedisclosed formulations are thought to be especially useful as "soft"hydrogel contact lenses. A lens is considered to be "soft" if it can befolded back upon itself without breaking.

A hydrogel is a hydrated cross-linked polymeric system that containswater in an equilibrium state. Silicone hydrogels (i.e., hydrogelscontaining silicone) are usually prepared by polymerizing a mixturecontaining at least one silicone-containing monomer and at least onehydrophilic monomer. Either the silicone-containing monomer or thehydrophilic monomer may function as a crosslinking agent (acrosslinker), being defined as a monomer having multiple polymerizablefunctionalities. Alternatively, an additional crosslinker may beemployed.

When the term "activated" is used with the term "unsaturated group"herein, it is meant that an unsaturated group which is activated is onewhich has a substituent which facilitates free radical polymerization.These activated unsaturated groups are polymerized to form the polymersof the present invention. Preferably the activating groups lendthemselves to polymerization under mild conditions, such as, ambienttemperatures.

When the term "polymerization" is used herein we refer to thepolymerization of the double bonds of the polysiloxanes endcapped withpolymerizable unsaturated groups which results in a crosslinked threedimensional network.

Further, notations such as "(meth)acrylate" or "(meth)acrylamide" areused herein to denote optional methyl substitution. Thus, for example,(meth)acrylate includes both acrylate and methacrylate andN-alkyl(meth)acrylamide includes both N-alkyl acrylamide and N-alkylmethacrylamide.

The term "prepolymer" denotes a monomer which may be a high molecularweight monomer containing at least two polymerizable groups. Themonomers added to the monomeric mixture of the present invention may bemonomers or prepolymers. Thus, it is understood that the terms"silicone-containing monomers" and "hydrophilic monomers" includecorresponding prepolymers. Examples of such monomers can be found inU.S. Pat. Nos. 4,136,250; 4,153,641; 4,740,533; 5,034,461 and 5,070,215.

The terms "shaped articles for use in biomedical applications" or"biomedical devices or materials" mean the hydrogel materials disclosedherein have physicochemical properties rendering them suitable forprolonged contact with living tissue, blood and the mucous membranes.

The monomers of the present invention can be used to produce highlywettable hydrogels with ideal rigidity, oxygen permeability and otherphysical properties. Such silicone-containing hydrogels are well-suitedfor use as biomedical devices such as contact lenses.

Certain crosslinked polymeric materials, such as those contemplated bythe present invention, may be polymerized to form a hard water-freexerogel. Xerogels are understood to be unhydrated hydrogel formulationswhich may be physically altered to, for example, impart opticalproperties through machining, and then be hydrated and retain theirwater content and optical properties.

Preferred acrylic-capped polysiloxane monomers of the present inventionare those having from about 1 to about 200 repeating siloxy units, andmost preferably have about 100 repeating siloxy units.

The fluorinated bulky polysiloxanylalkyl (meth)acrylate-containingmonomers of the present invention are excellent materials for use withboth "hard" and "soft" systems which may or may not be hydrogels. Thepreferred bulky polysiloxanylalkyl (meth)acrylate containing monomersare, for example, methacryloxypropyltris(octafluoropentyl-oxypropyldimethylsiloxy)silanes.

The preferred fluorinated side groups are the alkyl fluorinated sidechains, such as the propyloxyoctafluoropentanes, thepropyloxytetrafluoropropanes and the propyloxydodecaheptanes, with thepropyloxy octafluoropentanes being the most preferred.

The present invention contemplates, in one preferred embodiment,polymerizing, in a monomer mix, more than one type of polysiloxanemonomer, one of which has at least one polar fluorinatedsiloxane-containing monomer, with at least two hydrophilic monomers toproduce a contact lens material.

Additional hydrophilic monomers may be incorporated into the polymericcompositions contemplated by the present invention to form hydrogels.Such preferred hydrophilic monomers may be either acrylic- orvinyl-containing and may be used as crosslinking agents. The term"vinyl-type" or "vinyl-containing" monomers refers to non-acrylicmonomers containing the vinyl grouping (CH₂ ═CH₂). Such hydrophilicvinyl-containing monomers are known to polymerize relatively easily."Acrylic-type" or "acrylic-containing" monomers are those monomerscontaining the acrylic group ##STR7## wherein R is H or CH₃, and X is Oor NH.

Preferred hydrophilic vinyl-containing monomers which may beincorporated into the hydrogels of the present invention includemonomers such as N-vinyl lactams (e.g. N-vinyl pyrrolidone (NVP)),N-vinyl-N-methyl acetamide, N-vinyl-N-ethyl acetamide, N-vinyl-N-ethylformamide, N-vinyl formamide, with NVP being the most preferred.

Preferred hydrophilic acrylic-containing monomers which may beincorporated into the hydrogel of the present invention includehydrophilic monomers such as N,N-dimethyl acrylamide (DMA),2-hydroxyethyl methacrylate, glycerol methacrylate, 2- hydroxyethylmethacrylamide, methacrylic acid and acrylic acid, with DMA being themost preferred.

The relative ratio (wt. %) of siloxane-containing monomer to total wt. %of comonomer mix is preferably from about 10% to about 85%, morepreferably from about 20% to about 70%, and most preferably from about25% to about 40%. The relative ratio (wt. %) of hydrophilic monomer(s)to total wt. % of the comonomer mix is preferably from about 20% toabout 90%, more preferably from about 30% to about 80%, and mostpreferably from about 50% to about 60%.

The preferred silicone-containing vinyl carbonate or vinyl carbamatemonomers include:1,3-bis[4-vinyloxycarbonyloxy)but-1-yl]tetramethyl-disloxane;3-(trimethylsilyl)propyl vinyl carbonate;3-(vinyloxycarbonylthio)propyl-[tris(trimethylsiloxy)silane];3-[tris(trimethylsiloxy)silyl]propyl vinyl carbamate;3-[tris(trimethylsiloxy)silyl]propylallyl carbamate;3-[tris(trimethylsiloxy)silyl]propyl vinyl carbonate;t-butyldimethylsiloxyethyl vinyl carbonate; trimethylsilylethyl vinylcarbonate; trimethylsilylmethyl vinyl carbonate; and "V₂ D₂₅ " as shownin the following formula: ##STR8## wherein X is an alkyl or alkylenegroup having 1 to 10 carbon atoms and which may have ether linkagesbetween carbon atoms; and

z is 1 to 20.

When it is desirable for both an acrylic-containing hydrophilic monomerand a vinyl-containing hydrophilic monomer to be incorporated into thesilicone-containing polymer of the present invention, a furthercrosslinking agent having both a vinyl and an acrylic polymerizablegroup may be used, since these vinyl and acrylic hydrophilic monomershave different reactivity ratios and copolymerize at vastly differentrates or will not copolymerize at all. Such crosslinkers, such asmethacryloxyethyl vinyl carbonate (HEMAVc) and methacryloylethyl vinylcarbamate, which facilitate the copolymerization of the comonomers andare the subject of presently co-pending and commonly assigned U.S. pat.application Ser. No. 07/922,452 filed Jul. 30, 1992. Such crosslinkersare represented by the following schematic representation: ##STR9##wherein V denotes a vinyl-containing group having the formula: ##STR10##A' denotes an acrylic-containing group having the formula: ##STR11## Sdenotes a styrene-oontaininq group having the formula: ##STR12## whereinR₁₁ is an alkyl radical derived from substituted and unsubstitutedhydrocarbons, polyalkylene oxide, poly(perfluoro) alkylene oxide,dialkyl-capped polydimethylsiloxane, dialkyl-capped polydimethylsiloxanemodified with fluoroalkyl or fluoroether groups;

R₁₂ -R₂₀ are independently H, or alkyl of 1 to 5 carbon atoms;

Q is an organic group containing aromatic moieties having 6-30 carbonatoms;

X, Y, and Z are independently O, NH or S;

v is 1, or higher; and

a, s are independently greater than or equal to 0, and

a+s is greater than or equal to 1.

Such crosslinkers help to render the resulting copolymer totallyUV-curable. However, the copolymer could also be cured solely byheating, or with a combined UV and heat regimen. Therefore, it isunderstood that the necessary photo and thermal initiators required tocure the copolymer may be comprised therein as would be apparent tothose skilled in the art.

Other crosslinking agents which may be incorporated into thesilicone-containing hydrogel of the present invention include polyvinyl,typically di- or tri-vinyl monomers, most commonly the di- ortri(meth)acrylates of dihydric ethylene glycol, triethylene glycol,butylene glycol, hexane-1,6-diol, thio-diethylene glycol-diacrylate andmethacrylate; neopentyl glycol diacrylate; trimethylolpropanetriacrylate and the like; N,N'-dihydroxyethylene-bisacrylamideand-bismethacrylamides; also diallyl compounds like diallyl phthalateand triallyl cyanurate; divinylbenzene; ethylene glycol divinyl ether;and the (meth)acrylate esters of polyols such as triethanolamine,glycerol, pentanerythritol, butylene glycol, mannitol, and sorbitol.Further, illustrations include N,N-methylene-bis-(meth)acrylamide,sulfonated divinylbenzene, and divinylsulfone. Also useful are thereaction products of hydroxyalkyl (meth)acrylates with unsaturatedisocyanates, for example the reaction product of 2-hydroxyethylmethacrylate with 2-isocyanatoethyl methacrylate (IEM) as disclosed inU.S. Pat. No. 4,954,587.

Other known crosslinking agents arepolyether-bisurethane-dimethacrylates as described in U.S. Pat. No.4,192,827, and those crosslinkers obtained by reaction of polyethyleneglycol, polypropylene glycol and polytetramethylene glycol with2-isocyanatoethyl methacrylate (IEM) or m-isopropenyl-γγ,-dimethylbenzyl isocyanates (m-TMI), andpolysiloxane-bisurethane-dimethacrylates as described in U.S. Pat. Nos.4,486,577 and 4,605,712. Still other known crosslinking agents are thereaction products of polyvinyl alcohol, ethoxylated polyvinyl alcohol orof polyvinyl alcohol-co-ethylene with 0.1 to 10 mol % vinyl isocyanateslike IEM or m-TMI.

The instant copolymers can be readily cured to cast shapes byconventional methods such as UV polymerization, use of free radicalthermal initiators or heat, or combinations thereof, as commonly used inpolymerizing ethylenically unsaturated compounds. Representative freeradical thermal polymerization initiators are organic peroxides, such asacetal peroxide, lauroyl peroxide, decanoyl peroxide, stearoyl peroxide,benzoyl peroxide tertiarybutyl peroxypivalate, peroxydicarbonate, andthe like, employed in a concentration of about 0.01 to 1 percent byweight of the total monomer mixture. Representative UV initiators arethose known in the field such as, benzoin methyl ether, benzoin ethylether, Darocure 1173, 1164, 2273, 1116, 2959, 3331 (EM Industries) andIgracure 651 and 184 (Ciba-Geigy).

In addition to the above-mentioned polymerization initiators andcrosslinking agents, the monomeric mix and resulting copolymer of thepresent invention may also include additional materials such ascolorants, toughening agents, UV-absorbing agents and other materialssuch as those known in the contact lens art.

The resulting polymers of this invention can be formed into contactlenses by the spincasting processes such as those disclosed in U.S. Pat.Nos. 3,408,429 and 3,496,254 and other conventional methods, such ascompression molding as disclosed in U.S. Pat. Nos. 4,084,459 and4,197,266.

Polymerization may be conducted either in a spinning mold, or astationary mold corresponding to a desired contact lens shape. Thethus-obtained contact lens may be further subjected to a mechanicalfinishing, as occasion demands. Also, the polymerization may beconducted in an appropriate mold or vessel to give a lens material inthe form of button, plate or rod, which may then be processed (e.g., cutor polished via lathe or laser) to give a contact lens having a desiredshape.

The hydrogels produced by the present invention are oxygen transporting,hydrolytically stable, biologically inert, and transparent. The monomersand copolymers employed in accordance with this invention, are readilypolymerized to form three dimensional networks which permit thetransport of oxygen and are optically clear, strong and hydrophilic.

The present invention provides materials which can be usefully employedfor the fabrication of prostheses such as heart valves and intraocularlenses, as optical contact lenses or as films. More particularly, thepresent invention concerns contact lenses.

The present invention further provides articles of manufacture which canbe used for biomedical devices, such as, surgical devices, heart valves,vessel substitutes, intrauterine devices, membranes and other films,diaphragms, surgical implants, blood vessels, artificial ureters,artificial breast tissue and membranes intended to come into contactwith body fluid outside of the body, e.g., membranes for kidney dialysisand heart/lung machines and the like, catheters, mouth guards, dentureliners, intraocular devices, and especially contact lenses.

It is known that blood, for example, is readily and rapidly damaged whenit comes into contact with artificial surfaces. The design of asynthetic surface which is antithrombogenic and nonhemolytic to blood isnecessary for prostheses and devices used with blood.

The following examples serve only to further illustrate aspects of thepresent invention and should not be construed as limiting the invention.

EXAMPLE 1 Preparation of allyloxyoctafluoropentane

To a three-neck round bottom flask equipped with a mechanical stirrerand thermometer is added allyl bromide (16.9 g, 0.14 mole),octafluoro-1-pentanol (27.2 g, 0.1 mole), tetrabutylammonium hydrogensulfate (1.7 g, 0.005 mole), 10 mls of 50% sodium hydroxide and 125 mls.of tetrahydrofuran. The reaction shown below is complete following sixhours of reflux (70 degrees C.) as determined by GC. The resultantsolution is washed two times with distilled water. The product layer iscollected and distilled (68 degrees C./30mm) to give 31 grams (70%)yield of allyloxyoctafluoropentane. ##STR13## When z is 4 and 6,allyloxyoctafluoropentane and allyloxydodecafluoropentane side chainsare produced respectively.

EXAMPLE 2 Preparation of a DP 100 methacrylate end-capped poly 75 mole %dimethyl siloxane-co-25 mole % methyl siloxane hydride prepolymer

To a 1000 ml round bottom flask under dry nitrogen is addedoctamethylcyclotetrasiloxane (371.9 g, 1.25 mole), tetramethylcyclotetrasiloxane (100.4 g, 0.42 mole) and 1-3,bis-methacryloylbutyltetramethyldisiloxane (27.7 g, 0.7 mole).Trifluoromethane sulfonic acid (0.25% , 1.25 g) is added as initiator.The reaction mixture is stirred overnight at room temperature. Ten (10)grams of sodium bicarbonate is then added and the reaction mixture isagain stirred overnight. The resultant solution is then filtered andplaced under high vacuum at 50 degrees C. to remove the unreacted cycliccompounds. The monomer structure is confirmed by ¹ H-NMR spectroscopy.

EXAMPLE 3 Preparation of a DP 100 methacrylate end-capped poly 75 mole %dimethylsiloxane-co-poly 25 mole % methyl octfluoropentyloxypropylsiloxane monomer (Octa-25)

To a 500ml round bottom flask equipped with a magnetic stirrer and watercondenser, is added 15 g (0.002 mole) of the silicone hydride monomer(as prepared in Example 1 2), 27.2 g (0.1 mole) ofallyloxyoctafluoropentane (from example 2), 2.5 mls oftetramethyldisiloxane platinum complex (Huels- 3% Pt in xylene) and 150mls of anhydrous tetrahydrofuran (THF) and 75 mls dioxane under drynitrogen. The reaction mixture as shown below is heated to 75 degrees C.and the reaction is monitored by IR spectroscopy for loss of siliconehydride. When the silicone hydride is removed (3-4 hours), the reactionmixture is cooled and the unreacted allyloxyoctafluoropentane is removedby heating the product under high vacuum at 50 degrees C. for one hour.The monomer structure is confirmed by ¹ H-NMR spectroscopy. ##STR14##where y is 10, 25 and 40;

x+y is 100; and

z is 4 and 6

EXAMPLE 4 Preparation of a methacryloylpropyl tris(dimethylsiloxy)silane

To a three neck round bottom flask equipped with a thermometer andmagnetic stirrer is added methacryloylpropyltrichlorosilane (2.5 g, 0.01mole), dimethylchlorosilane (6.53 g, 0.069 mole), triethylamine (7.69 g,0.076 mole) and 25 mls of anhydrous diethylether. The reaction mixtureis cooled to -15 degrees C. and distilled water (5 g, 0.28 mole) isslowly added. The reaction is allowed to come to room temperature slowlyand the reaction is stirred overnight. The resultant solution is washedthree times with distilled water. The ether layer is collected, driedover magnesium sulfate, filtered and the diethylether is removed using arotoevaporator. The resultant oil is vacuum distilled (83-93 degreesC./1mm) to give a 51.4 % yield of 97.5% pure (as determined by GC)methacryloylpropyl tris (dimethylsilyloxy)silane.

EXAMPLE 5 Preparation of a methacryloylpropyltris(octafluoropentyloxy-propyldimethylsilyloxy) silane

To a 200 ml round bottom flask is added methacryloylpropyl tris(dimethylsilyloxy) silane (5.0 g,0.013 mole), allyloxyoctafluoropentane(21.4 g, 0.079 mole), 0.005 ml of a platinum divinyl complex (Huels) and50 mls of tetrahydrofuran. The solution is refluxed for one hour atwhich time the silicone hydride is reacted as shown by ¹ H-NMRspectroscopy. The tetrahydrofuran and unreacted allyloxyoctafluoropentane is removed using a rotoevaporator (50 degrees C. at 30mm)resulting in a quantitative yield of methacryloylpropyl tris(octafluoropentyloxypropyldimethylsilyloxy)silane.

EXAMPLE 6 Physical Properties of Films Cast from 25 mole % octafluoro(octa-25) with dimethacrylamide (DMA)

All of the films cast for physical and mechanical property evaluationwere prepared using the following procedure. The films were cast betweensilanized glass plates using a Teflon gasket. The UV initiator wasDarocur 1173 (0.5% concentration). The cure conditions consisted ofirradiating the films for two hours with U.V. lamps at an intensity of3700 uW/cm². Following the cure, the films were extracted in 2-propanolovernight at room temperature (300% expansion), dried at roomtemperature for two hours and boiled for two hours in buffered saline.The films were evaluated for mechanical properties, O₂ permeability andhydrolytic stability. The hydrolytic stability test consisted of heatingthe test samples at 80 degrees C. in buffered saline and monitoring theweight loss at 3, 5 and 7 days.

Table 1 shows the extractable, water content, O₂ permeability andmechanical data for films cast from the DP100 methacrylate end-capped 25mole % octafluoro (octa-25) with dimethylacrylamide (DMA). No co-solventwas needed to solubilize the components. The films were transparent.

                  TABLE 1                                                         ______________________________________                                        Extractable, Water Content, Oxygen Permeability and Mechanical                Data for Octafluoro Siloxane/DMA Based Formulations                                  % Ex-   %            Modu- %     Ten-                                  Mix    tract.  Water   DK   lus   Elong.                                                                              sile Tear                             ______________________________________                                        100/0  11.97   0.00    530   55   40    18   1.5                              90/10  8.57    6.39    397  188   38    48   1.5                              80/20  7.24    18.18   223  219   34    48   3.3                              75/25  6.80    25.56   134  222   29    44   4.1                              70/30  5.78    30.94   138  210   63    68   3.1                              ______________________________________                                    

EXAMPLE 7 Comparative Example - Improved Solubility of the 25 mole %Octafluoro (octa-25) with Hydrophilic Monomers Compared with SiloxanesNot Having the --CF₂ --H Terminal Group

Formulations were prepared form 70 parts of a DP 100 methacrylateend-capped polydimethylsiloxane with 30 parts of DMA. The formulationgave a phase separated mixture. The polydimethylsiloxane and DMA wereincompatible. No attempt to cast films from this mixture was made. Inaddition, solutions were prepared from a DP 100 methacrylate end-cappedpolydimethylsiloxane containing 25 mole % nonafluoro side chain, (i.e.the terminal --CF₂ --H bond was replaced with a terminal fullyfluorinated --CF₃ group), with 30 parts of DMA. A phase separatedmixture resulted. The DMA and polysiloxane were incompatible. No attemptwas made to cast films from this mixture.

EXAMPLE 8 Film Data--Fluorosiloxane/DMA/VDMO

Table 2 shows the extractable, water content, O₂ permeability andmechanical property data for films prepared from the DP100 methacrylateend-capped 25 mole % octafluorosiloxane with DMA andvinyldimethyloxazolidinone (VDMO) as the hydrophilic monomers. All ofthe films prepared were transparent.

                  TABLE 2                                                         ______________________________________                                        25 mole % Octafluorosiloxane/DMA/VDMO                                         Formulation Properties                                                               % Ex-   %            Modu- %     Ten-                                  Mix    tract.  Water   DK   lus   Elong.                                                                              sile Tear                             ______________________________________                                        70/30  5.8     34      145  180   40    47   3.1                              70/30/1                                                                              6.4     33      132  156   39    37   2.9                              70/30/3                                                                              5.9     37      102  106   36    22   2.5                              70/30/5                                                                              5.0     42       66  103   50    30   2.6                              ______________________________________                                    

EXAMPLE 9 Film Data--Fluorosiloxane/TRIS/DMA/NVP

Tables 3 and 4 show the extractable, water content, O₂ permeability andmechanical property data for films cast from the 25 mole %octafluorosiloxane with methacryloxy propyl tris(trimethylsiloxy)silane(TRIS), DMA and N-vinylpyrrolidinone (NVP).

                  TABLE 3                                                         ______________________________________                                        25 mole % Octafluorosiloxane/TRIS/DMA/NVP                                     Formulation Properties                                                        Mix         % Water  DK       Modulus                                                                              Tear                                     ______________________________________                                        80/0/20/0   17       186      155    1.8                                      80/0/15/5   17       212      170    2.4                                      80/0/10/10  15       183      195    1.9                                      80/0/5/15   16       186      190    2.0                                      70/0/30/0   28       108      190    3.0                                      70/0/20/10  25       112      217    3.5                                      70/0/10/20  27       130      212    2.5                                      75/0/5/25   24       160      179    1.4                                      40/10/10/40 52        52       71    2.3                                      ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        25 mole % Octafluorosiloxane/TRIS/DMA/NVP/EGDMA                               Formulation Properties                                                        Mix         % Water  DK       Modulus                                                                              Tear                                     ______________________________________                                        50/0/10/40/0.2                                                                            41       65       171    2.4                                      40/10/10/40/0.2                                                                           46       63       83     2.3                                      25/25/10/40/0.2                                                                           51       81       32     4.5                                      10/40/10/40/0.2                                                                           54       76       20     9.2                                      ______________________________________                                         All formulations contain 20 parts hexanol.                                    EGDMA is ethylene glycol dimethacrylate.                                 

EXAMPLE 10 Film Data--Tris-Fluorosiloxane/DMA

Films were cast from the octafluoro substituted tris methacrylate (asprepared in Example 5) using DMA as a comonomer. A 70/30 octafluorosubstituted tris methacrylate/DMA formulation possessed a water contentof 25%, a Dk of 42, a modulus of 107 g/mm², and a tear strength of 3.7g/mm. In addition, films were also cast from the octafluoro substitutedtris methacrylate and NVP mixtures. The resultant films were transparentwithout the presence of a cosolvent in the monomer mix. A 70/30/0.5octafluoro substituted tris methacrylate/NVP/EGDMA formulation has awater content of 25%, a Dk of 45, a modulus of 107 g/mm² and a tearstrength of 3.7 g/mm.

EXAMPLE 11 Cast Molding of Octafluorosiloxane Based Lenses

Lenses were cast using the DP 100 methacrylate end-capped 25 mole %octafluoro side chain siloxane/DMA/Darocur 1173 (70/30/0.5) formulationusing the cure conditions listed in Example 8. The overall yield ofcosmetically acceptable lenses was 40%. Following a 2-propanol andbuffered saline extraction, the resultant lenses showed excellentwettability.

All formulations further contained 20 parts hexanol. Hydroxyethylmethacrylate vinyl carbonate (HEMAVC) and ethylene diglycol methacrylate(EDGMA) are used as crosslinking agents.

Many other modifications and variations of the present invention arepossible to the skilled practitioner in the field in light of theteachings herein. It is therefore understood that, within the scope ofthe claims, the present invention can be practiced other than as hereinspecifically described.

We claim:
 1. A method of improving the solubility of vinyl- andacryl-functional siloxane-containing monomers in a hydrophilic monomerwhich comprises attaching to the siloxane-containing monomers a polarfluorinated side group having a hydrogen atom attached to a terminaldifluoro-substituted carbon atom.
 2. A siloxane-containing monomerhaving at least one fluorinated side group and having the generalschematic representaton: ##STR15## wherein: R is an alkyl or alkylenegroup having 1 to 10 carbon atoms and which may have ether linkagesbetween carbon atoms;R₁ -R₄ may independently be a monovalenthydrocarbon radical or a halogen substituted monovalent hydrocarbonradical having 1 to 18 carbon atoms which may have ether linkagesbetween carbon atoms; x is ≧0; y is ≧1; x+y=2 to 1000; R₅ is afluorinated side group having the general schematic representation:

    --D--(CF.sub.2).sub.z --H

wherein z is 1 to 20; D is alkyl or alkylene group having 1 to 10 carbonatoms and which may have ether linkages between carbon atoms; and A isan activated unsaturated group.
 3. The monomer of claim 2 wherein saidfluorinated side group comprises an alkyloxyperfluoroalkyl group.
 4. Themonomer of claim 3 wherein said fluorinated side group is selected fromthe group consisting of propyloxyoctafluoropentanes,propyloxytetrafluoropropanes, and propyloxydodecafluoroheptanes.
 5. Thesiloxane-containing monomer of claim 3 wherein said fluorinated sidegroup is represented by the formula:

    --CH.sub.2 --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --(CF.sub.2).sub.z --H

wherein z is 1 to
 20. 6. The siloxane-containing monomer of claim 2wherein said siloxane-containing monomer is comprised of a repeatingnumber of between from about 2 to about 200 siloxy units.
 7. Thesiloxane-containing monomer of claim 2 wherein said siloxane-containingmonomer is comprised of about 100 repeating siloxy units.
 8. Afluorinated bulky polysiloxanylalkyl (meth)acrylate-containing monomerhaving the general schematic representation: ##STR16## wherein A is anactivated unsaturated group, such as an ester or amide of an acrylic ora methacrylic acid;R₆ is CH₃ or H; R is an alkyl or alkylene grouphaving 1 to 10 carbon atoms and which may have ether linkages betweencarbon atoms; D is an alkyl or alkylene group having 1 to 10 carbonatoms and which may have ether linkages between carbon atoms; x is 1, 2or 3; y is 0, 1 or 2; and x+y=3.
 9. A fluorinated bulkypolysiloxanylalkyl-containing monomer having the formula: ##STR17##wherein R₇ is CH_(2;) x is 1, 2 or 3; y is 0, 1 or 2; and x+y=3.
 10. Themonomer of claim 8 wherein said fluorinated side group comprises analkyloxyperfluoroalkyl group.
 11. The monomer of claim 10 wherein saidfluorinated side group is selected from the group consisting ofpropyloxyoctafluoropentanes, propyloxytetrafluoropropanes, andpropyloxydodecafluoroheptanes.
 12. The monomer of claim 10 wherein saidfluorinated side group is represented by the formula:

    --CH.sub.2 --CH.sub.2 --CH.sub.2 --O--CH.sub.2 --(CF.sub.2).sub.z --H

wherein z is 1 to
 20. 13. A monomer mix comprising at least onesiloxane-containing monomer which comprises a polar fluorinated sidegroup having a hydrogen atom attached to the terminaldifluoro-substituted carbon atom and at least one hydrophilic monomer.14. The monomer mix of claim 13 wherein said fluorinated side group hasthe general schematic representation:

    --D--(CF.sub.2).sub.z H

wherein z is 1 to 20; and D is an alkyl or alkylene group having 1 to 10carbon atoms and which may have ether linkages between carbon atoms. 15.The monomer mix of claim 14 wherein said monomer mix further comprisesat least one additional siloxane-containing monomer.
 16. The monomer mixof claim 14 wherein said monomer mix further comprises at least oneadditional crosslinking agent.